Adventure Time's characters have deceptively simple, pliable bodies, but Pendleton Ward's guide to drawing Finn and Jake reveals some very specific rules for how the boy and dog adventurers should look.

It's especially interesting to see what rules for Finn and Jake's appearances are kept deliberately loose (the number of fingers, the proportions of Finn's face-hole, the placement of elbows) and where the rules are stricter to maintain a sense of character and style (Finn's teeth, the actual curve of the elbow). Of course, now you can doodle deliberately incorrect Finns for fun.